Three dimensional printing apparatus

Abstract

A three-dimensional printing apparatus including a tank, a moving platform, a light source disposed below the tank, a detecting unit and a control unit is provided. The tank is filled with a liquid forming material and a separating liquid, wherein the specific density of the separating liquid is larger than the specific density of the liquid forming material, so that the separating liquid sinks between the tank and the liquid forming material. The control unit controls an initial depth at which the moving platform immerses into the liquid forming material, so as to form a three-dimensional object. A three-dimensional printing apparatus is also provided, wherein the light source thereof is disposed above the tank, and the specific density of the liquid forming material is larger than the specific density of the separating liquid, so that the liquid forming material sinks between the tank and the separating liquid.

What is claimed is: 
     
       1. A three-dimensional printing apparatus, comprising:
 a tank, filled with a liquid forming material and a separating liquid, wherein a specific density of the separating liquid is larger than a specific density of the liquid forming material, and the separating liquid and the liquid forming material are substantially immiscible with each other, so that the separating liquid sinks between the bottom of the tank and the liquid forming material; 
 a moving platform, movably disposed above the tank; 
 a light source, disposed below the tank so as to irradiate the liquid forming material; 
 a detecting unit, comprising an optical element disposed at a side of the tank, and adapted to move along an axial direction and to emit a ray of light towards the separating liquid and the liquid forming material, the axial direction is perpendicular to the junction between the separating liquid and the liquid forming material, and the light is parallel to the junction, so as to detect a junction between the separating liquid and the liquid forming material through the reflection of the light; and 
 a control unit, coupled to the light source, the detecting unit and the moving platform, wherein the control unit controls an initial depth at which the moving platform immerses into the liquid forming material, according to the junction detected by the detecting unit, the control unit controls the moving platform to move from the initial depth in the liquid forming material layer by layer towards a direction away from the light source, and controls the light source to irradiate the liquid forming material, so as to cure the irradiated liquid forming material layer by layer, thereby forming a three-dimensional object on the moving platform. 
 
     
     
       2. The three-dimensional printing apparatus as recited in  claim 1 , further comprising:
 a first injection module, connected to the tank, so as to inject a certain amount of the separating liquid into the tank, and when a liquid level position of the separating liquid is lower than a preset value, the control unit controls the first injection module to inject the separating liquid into the tank; and 
 a second injection module, connected to the tank, so as to inject a certain amount of the liquid forming material into the tank, and when a liquid level position of the liquid forming material is lower than a preset value, the control unit controls the second injection module to inject the liquid forming material into the tank. 
 
     
     
       3. The three-dimensional printing apparatus as recited in  claim 2 , wherein the first injection module has a first injection opening, the second injection module has a second injection opening, the first injection opening and the second injection opening are respectively connected with the tank, and a relative distance from the first injection opening to the bottom of the tank is smaller than a relative distance from the second injection opening to the bottom of the tank. 
     
     
       4. The three-dimensional printing apparatus as recited in  claim 1 , wherein the detecting unit comprises an ultrasonic element disposed below the tank, the ultrasonic element is adapted to emit an ultrasonic wave along an axial direction and towards the separating liquid and the liquid forming material, and the axial direction is perpendicular to the junction between the separating liquid and the liquid forming material, so as to detect the junction through the reflection of the ultrasonic wave. 
     
     
       5. The three-dimensional printing apparatus as recited in  claim 1 , wherein the detecting unit comprises a floating ball disposed within the tank, a specific density of the floating ball ranges between the specific density of the separating liquid and the specific density of the liquid forming material, and the floating ball is adapted to float between the separating liquid and the liquid forming material, so as to detect the junction between the separating liquid and the liquid forming material through a floating position of the floating ball. 
     
     
       6. The three-dimensional printing apparatus as recited in  claim 1 , wherein the liquid forming material comprises a photosensitive resin, and the separating liquid comprises saline water. 
     
     
       7. The three-dimensional printing apparatus as recited in  claim 1 , wherein the moving platform is adapted to move in relative to the tank along an axial direction, the axial direction is perpendicular to the junction between the separating liquid and the liquid forming material, and the control unit uses the junction as the initial depth at which the moving platform immerses into the liquid forming material. 
     
     
       8. A three-dimensional printing apparatus, comprising:
 a tank, filled with a liquid forming material and a separating liquid, wherein a specific density of the liquid forming material is larger than a specific density of the separating liquid, and the separating liquid and the liquid forming material are substantially immiscible with each other, so that the liquid forming material sinks between the bottom of the tank and the separating liquid; 
 a moving platform, movably disposed above the tank; 
 a light source, disposed above the tank so as to irradiate the liquid forming material; 
 a detecting unit, comprising an optical element disposed at a side of the tank, and adapted to move along an axial direction and to emit a ray of light towards the separating liquid and the liquid forming material, the axial direction is perpendicular to the junction between the separating liquid and the liquid forming material, and the light is parallel to the junction, so as to detect a junction between the separating liquid and the liquid forming material through the reflection of the light; and 
 a control unit, coupled to the light source, the detecting unit and the moving platform, wherein the control unit controls an initial depth at which the moving platform immerses into the liquid forming material according to the junction detected by the detecting unit, the control unit controls the moving platform to move from the initial depth in the liquid forming material layer by layer towards a direction away from the light source, and controls the light source to irradiate the liquid forming material, so as to cure the irradiated liquid forming material layer by layer, thereby forming a three-dimensional object on the moving platform. 
 
     
     
       9. The three-dimensional printing apparatus as recited in  claim 8 , further comprising:
 a first injection module, connected to the tank, so as to inject a certain amount of the separating liquid into the tank, and when a liquid level position of the separating liquid is lower than a preset value, the control unit controls the first injection module to inject the separating liquid into the tank; and 
 a second injection module, connected to the tank, so as to inject a certain amount of the liquid forming material into the tank, and when a liquid level position of the liquid forming material is lower than a preset value, the control unit controls the second injection module to inject the liquid forming material into the tank. 
 
     
     
       10. The three-dimensional printing apparatus as recited in  claim 9 , wherein the first injection module has a first injection opening, the second injection module has a second injection opening, the first injection opening and the second injection opening are respectively connected with the tank, and a relative distance from the first injection opening to the bottom of the tank is larger than a relative distance from the second injection opening to the bottom of the tank. 
     
     
       11. The three-dimensional printing apparatus as recited in  claim 8 , wherein the detecting unit comprises an ultrasonic element disposed below the tank, the ultrasonic element is adapted to emit an ultrasonic wave along an axial direction and towards the separating liquid and the liquid forming material, and the axial direction is perpendicular to the junction between the separating liquid and the liquid forming material, so as to detect the junction through the reflection of the ultrasonic wave. 
     
     
       12. The three-dimensional printing apparatus as recited in  claim 8 , wherein the detecting unit comprises a floating ball disposed within the tank, a specific density of the floating ball ranges between the specific density of the separating liquid and the specific density of the liquid forming material, and the floating ball is adapted to float between the separating liquid and the liquid forming material, so as to detect the junction between the separating liquid and the liquid forming material through a floating position of the floating ball. 
     
     
       13. The three-dimensional printing apparatus as recited in  claim 8 , wherein the liquid forming material comprises a photosensitive resin, and the separating liquid comprises water. 
     
     
       14. The three-dimensional printing apparatus as recited in  claim 8 , wherein the moving platform is adapted to move in relative to the tank along an axial direction, the axial direction is perpendicular to the junction between the separating liquid and the liquid forming material, and the control unit uses the junction as the initial depth at which the moving platform immerses into the liquid forming material.